Validation and popularization of combinations of fungicides in spray schedule for management of premature leaf fall (c.o. Marssonina coronaria) in Shimla hills

Usha Sharma, NS Kaith* and Bhupesh Gupta

Regional Horticultural Research & Training Station, Dr YS Parmar University of Horticulture & Forestry, Mashobra, Shimla-171007 HP

*Krishi Vigyan Kendra, Shimla, Dr YS Parmar University of Horticulture & Forestry, Rohru, Shimla-171207 HP

Abstract

Apple is one of the most important cash crops of the hill states of India. Among various diseases, Marssonina blotch has become a major bottleneck in successful apple cultivation. During 2007 and 2008, survey conducted in different blocks of district Shimla, Himachal Pradesh revealed 50 to 95 percent of the disease incidence. An effort was made to validate recommended fungicide combinations for the effective management of premature leaf fall. Orchards in locations with high humidity, high temperature, poor canopy and poor floor management were selected to validate and demonstrate the technology. Three different schedules were tried with recommended fungicides and their combinations. Schedule III has shown least disease incidence 5.73 and 5.0 percent during year 2009-2010 and 2010-11 respectively, that was at par with schedule II (8.33 and 7.00%). All the three schedules were found effective in the management of the disease as compared to farmer’s practice. Improvement in disease control due to reduction in inoculum was clearly seen from the demonstration trials laid out in 2011-12 (95.27%) and 2012-13 (93.35%), the schedule III was taken up against farmers’ practice for demonstration.

Key words: Premature leaf fall, management, Marssonina coronaria

Usha Sharma (corresponding author)

Email id.

Introduction:

Apple is one of the most important temperate fruit crops in terms of land use efficiency with better opportunities for higher returns, friendly environment and employment generation. In India, it is commercially grown in the states of Jammu & Kashmir, Himachal Pradesh, Kumaun and Garhwal hills of Uttrakhand and parts of Sikkim and Arunachal Pradesh. In Himachal Pradesh, apple cultivation has revolutionized the socio-economic conditions of farmers and it is a leading commercial fruit crop being cultivated over 110679 ha with annual production of 777126 M tones (Anonymous, 2016). However, during past two decades, Marssonina blotch/ premature leaf fall caused by Marssonina coronaria has become a major bottleneck in successful apple cultivation in Shimla, Mandi, Kullu and Kinnaur districts of Himachal Pradesh. Premature leaf shedding in apple has also been reported from Jammu & Kashmir, Uttarakhand and Bhutan (Sharma and Verma, 1999). The disease starts appearing in the months of May-June, and by the mid of August, most of ill managed orchards are severely affected with typically leaf spotting, yellowing and falling of leaves, ultimately, fruits near maturity are generally seen hanging from defoliated branches (Figure 1) of affected trees (Sharma and Gautam, 1997).

In Himachal Pradesh, every year an integrated spray schedule is released for the management of fungal diseases in apple by the Department of Horticulture, in collaboration with Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan, HP recommending different fungicidal sprays at different stages.

To validate various recommended fungicide combinations for the effective management of premature leaf fall, multilocational trials were conducted. Further, demonstrations were conducted to popularize the best technology found in validation trials for the management of the disease, besides, field days and training programmes were organized on trials sites to disseminate proper canopy and orchard floor management practices for reduction of primary inoculum thus effective management.

Materials and Methods:

Analysis of factors responsible for outbreak of disease:

A survey was conducted in different blocks of the district Shimla, Himachal Pradesh, during 2007-08 and 2008-09, to know the reasons for high incidence of premature leaf fall and to select orchards to conduct location specific trials and demonstrations. Locations having the micro climate of high humidity and temperature that are pre-disposing factors for disease development were found to have high disease incidence. Other factors, which favored the spread of the disease in the orchard are:

  1. Dense canopy favours high humidity and poor aeration during fruiting period in the orchard and is major disposing factor for high disease severity.
  2. The farmers were spraying fungicides upto drip-off situation and, not using prophylactic sprays for the management of the disease.
  3. Moreover, farmers using mixtures of fungicides, insecticides and nutrients on routine basis, which contribute in aggravating the severity of disease, inspite of disease management.

Action Plan:

All important factors of the premature leaf fall/ Marssonina leaf blotch development in apple were taken into consideration to manage the disease. Twenty three different apple orchards were selected representing the specific microclimatic conditions. High humidity and poor aeration were the important pre-disposing factors in disease development, aggravated by dense canopy and poor orchard floor management practices. Therefore, to create awareness among farmers about the proper management practices i.e. canopy and orchard floor management, training programs were organized with scientist of fruit science in the surveyed areas of the district during the years 2007-11. Demonstrations on canopy management were given to farmers to enhance penetration of sunlight and aeration in tree canopy. Floor management by manual weeding in the basin areas of the tree from time to time (May to August) was also demonstrated, which helped in reducing the humidity in the canopy of the tree and improving aeration in the orchard.

Keeping in view the losses resulted due to the disease, On Farm Trials (OFTs) at five locations (two in Rohru, one each at Chirgaon, Jubbal and Kotkhai) in district Shimla, Himachal Pradesh were conducted for the management of the disease by using three different combinations of fungicides selected from spray schedule of Department of Horticulture, Himachal Pradesh and Dr YS Parmar University of Horticulture and Forestry, Solan released during the year 2009-10. The sprays were given as per schedule given in Table 1. Treatment which was found best in the year 2009-10 and 2010-11 in OFTs for the management of disease, were validated and demonstrated at different ten locations (3 locations each at Rohru and Chirgaon, two each at, Jubbal and Kotkhai) during the years 2011-12 and 2012-13.

Results and Discussion:

Apple growing areas of district Shimla, Himachal Pradesh, were conducted from May to August months in 2007 and 2008 to determine the Marssonina blotch/ premature leaf fall occurrence in apple orchards. The incidence of Marssonina blotch ranged between 50 to 95 percent in different orchards with highest 95 percent in an orchard located at Karalash in Rohru block out of twenty three orchards selected of district Shimla (Table 2).

Use of suitable fungicidal sprays at proper stage with canopy and floor management gave excellent results in comparison to farmers’ practice. A spray schedule with fungicide combination of mancozeb 75 WP (500g) + carbendazim 50 WP (100g) at walnut stage, followed by propineb 70 WP (600g) at fruit development stage (20 days after previous spray, dodine 65 WP (150g) at fruit development stage (20 days after previous spray) and carbendazim 50WP (100g) at preharvest stage (20-25 days before harvest) all per 200 liters of water, was found best with minimum disease incidence i.e. 5.73 (13.77) and 5.00 (13.33) percent during 2009-10 and 2010-11, respectively, and was found at par with schedule II in both the years, followed by spray schedule I (Table 3). The percent disease incidence in control treatment (farmers’ practice) was very high i.e. 79.77 (63.76) and 60.77 (51.30) during 2009-10 and 2010-11, respectively (Table 3). In 2011-12 and 2012-13, the Schedule III, which was found best during 2009-10 and 2010-11, was demonstrated on farmer’s field and percent disease control 95.27 and 93.35 was recorded in demonstration plots, whereas percent disease incidence 84.42 and 76.08 percent was recorded in farmers’ practice, respectively (Table 4).

Earlier studies indicated that protective sprays of mancozeb, carbendazim, dodine etc were effective for the management of premature leaf fall (Sharma and Gautam, 1997; Sharma et al 2004; Thakur and Sharma, 2010). Spray schedule having combination of different fungicides i.e. mancozeb 75 WP (500g) + carbendazim 50 WP (100g) at walnut stage, followed by propineb (600g) at fruit development stage (20 days after previous spray, dodine (150g) at fruit development stage (20 days after previous spray) and carbendazim 50WP (100g) at preharvest stage (20-25 days before harvest) was found best in controlling the disease during the year 2011-12 and 2012-13 in comparison to farmers’ practice in demonstration trials. Similarly, integrated sprays of fungicides at different fruit development stages have been found were effective in management of premature leaf fall by Sharma and Bhardwaj (2003).

References:

Anonymous.2016. http//.hphorticulture.nic.in

Sharma I M and Bhardwaj S S. 2003. Efficacy and economics of different fungicide spray schedule in controlling premature leaf fall of apple. Plant Disease Research 18: 21-24.

Sharma J N and Gautam D R. 1997. Studies on premature leaf fall of apple –a new problem. Journal of Plant Protection 25: 8-12.

Sharma J N, Sharma Anita and Sharma Pankaj. 2004. Outbreak of Marssonina blotch in warmer climates causing premature leaf fall problem of apple and its management. Acta Horticulturae 662: 405-409.

Sharma J N and Verma L R. 1999. Premature leaf fall problem in apple: diagnosis and control. In: Diseases of Horticultural Crops- Fruits, (Eds. Verma L R and Sharma R C). Indus Publishing Co., New Delhi, pp.81-88.

Thakur V S and Sharma Nirupma. 2010. Epidemic outbreak of apple blotch disease: epidemiology and management in Himachal Pradesh. Indian Phytopathology 63(2):141-144.

Table1. Different fungicides spray schedule evaluated for management of Marssonina blotch /premature leaf fall in apple

Stage / Fungicide spray schedule
I / II / III
Walnut size / Mancozeb 75 WP (600gm)* / Zineb 75 WP(600 gm) / Mancozeb 75 WP (500gm) + carbendazim 50 WP(100 gm)
Fruit Development (20 days after above) / Carbendazim 50 WP(100 gm) / Thiophenate Methyl 70 WP (100gm) / Propineb 70 WP (600gm)
Fruit development
(20 days after above) / Propineb 70 WP (600gm) / Mancozeb 75WP (600 gm) / Dodine 65 WP (150gm)
Preharvest (20-25 days before harvest) / Ziram 27 SL (600ml) / Carbendazim 50 WP (100 gm) / Carbendazim 70 WP (100 gm)

*quantity used per 200 liters of water

Table2. Incidence of Marssonina blotch/ premature leaf fall in apple orchards in different orchards of Shimla district, Himachal Pradesh

Orchard No. / Location / Percent Incidence
Orchard No.1 / Karalash orchards 1, Rohru / 95
Orchard No.2 / Karalash orchards 2, Rohru / 50
Orchard No.3 / Karalash orchards 3, Rohru / 56
Orchard No.4 / Karalash orchards 4, Rohru / 73
Orchard No.5 / Karalash orchards 5, Rohru / 81
Orchard No.6 / Buthara, Rohru / 52
Orchard No.7 / Kutara, Rohru / 67
Orchard No.8 / Dalgaon, Rohru / 78
Orchard No.9 / Dhara orchards 1, Rohru / 60
Orchard No.10 / Dhara orchards 2, Rohru / 78
Orchard No.11 / Dhara orchards 3, Rohru / 89
Orchard No.12 / Jatata, Chirgaon / 91
Orchard No.13 / Paija, Chirgaon / 53
Orchard No.14 / Khashdhar orchards 1, Chirgaon / 62
Orchard No.15 / Khashdhar orchards 2, Chirgaon / 75
Orchard No.16 / Nauda orchards 1, Chirgaon / 51
Orchard No.17 / Nauda orchards 2, Chirgaon / 53
Orchard No.18 / Pangna, Jubbal / 59
Orchard No.19 / Shari, Jubbal / 90
Orchard No.20 / Sawara, Jubbal / 73
Orchard No.21 / Kokunal, Kotkhai / 55
Orchard No.22 / Khaneti Orchard 1, Kotkhai / 75
Orchard No.23 / Khaneti Orchard 2, Kotkhai / 70

Table 3. Efficacy of different fungicide combinations in controlling Marssonina coronaria causing premature leaf fall in apple

Treatment / Percent Disease Incidence*
2009-10 / 2010-11
Schedule I / 13.33 / (21.34) / 10.33 / (19.79)
Schedule II / 8.33 / (16.71) / 7.00 / (15.83)
Schedule III / 5.73 / (13.77) / 5.00 / (13.13)
Control (Farmers’ practice) / 79.77 / (63.76) / 60.77 / (51.30)
C.D.= / 4.840 / 4.860

*Pooled data for five location

Table 4. Efficacy of Schedule III in controlling Marssonina coronaria in apple during Front Line Demonstrations.

Treatment / 2011-12 / 2012-13
Percent Disease Incidence* / Percent Disease Control / Percent Disease Incidence* / Percent Disease Control
Schedule III / 3.99 / (9.88) / 95.27 / 5.06 / (9.064) / 93.35
Control (Farmers’ practice) / 84.42 / (67.27) / 76.08 / (61.92)
CD / 4.556 / 5.019

*Pooled data for ten locations